Lubricating oil



Patented Mar. 14, 1939 2,150,111 LUBRICATING on.

Bert H. Lincoln and Gordon D. Byrkit, Ponca City, Okla., assig'nors, bymesne assignments, to The Lubri-Zol Development Corporation, Cleveland,Ohio, a. corporation of Delaware No Drawing. Application April 15, 1935,

' Serial No. 16,410

3 Claims.

This invention relatesto lubricating oil and specifically to acomposition of matter having many desirable characteristics forpractical lubrication.

5 In the manufacture of lubricating oil designed for use in modernautomotive equipment, the demands on the lubricants have increasedmarkedly in recent years. While the low speed engines designed withBabbitt bearings operating with comparatively large clearances betweenthe journals and bearings required no exceptional properties in thelubricating oil, the modern high speed engines using harder journals andbearings operating at much smaller clearances require that thelubricating oil possess a variety of unusual characteristics in order tolubricate this type of englne satisfactorily. Among thesecharacteristics are increased stability toward heat and oxidation,reduced tendency to develop sludge and acidity in use, and mostimportant of all, the ability to carry high loads without permittingmetal-to-metal contact. The necessity of these properties, particularlythat of high film strength in lubricating oils, is emphasized in all theliter ature treating of lubrication of modern automotive equipment.Thus, for example, in the National Petroleum News, vol. 27, #5, page 25(January 30, 1935), numerous recommendations for the use of extremepressure lubricants in modern automobiles are cited. The use of suchaddition agents may aiiect either favorably or adversely such otherproperties of the hydrocarbon oil asstability toward heat and oxidation,corrosiveness after use, cold test, and other important properties. Inthe design of the addition agent such othervefi'ects must be considered,since the hard alloy bearings are very susceptible to corrosion, forexample, by acids derived from both the addition agent and thehydrocarbon base. Unless very soluble addition agents are used, the coldtest of the blended oil may beraisedw This isa distinct disadvantage,particularly in winter grade oils. Some addition agents may accelerateoxidation of the oil, while others may be without effect or evendecrease the susceptibility to oxidation during use: All of the efiectsof the addition agent on the blend must therefore be considered indesigning a material for the improvement of the load carrying ability ofthe oil.

- In the previous art of preparing addition agents for the improvementof the film strength of lubricating oils, no cognizance has been takenof the relation between. the molecular structure of the organic moleculeand its effect on the properties of the oil with which it is blended. Wehave 5 discovered that the presence of particular functional groups andtheir position in the organic molecule have a profound effect upon theability of the material to raise the load carrying emciency of themineral oil with which it is blended.

-We have discovered that the introduction of negative radicals, moreparticularly the phenyl or substituted phenyl group, into the moleculeof a halogenated compound serves to activate the halogen in such a waythat the arylated compound is many times more efiective as an extreme prssure compound than the unarylated compound. This improvement whicharylation effects in extreme pressure character is not attended by anydeleterious change in any other properties of the 20 addition agent, butthe introduction of the aryl group often improves the other propertiesof the essence so that the blended oil may have betterv stability withrespect to heat and oxidation, better color after use, and otherdesirable charac- 25 teristics. The presence of halogen in an arylradical will increase its negativity. In view of this we have used theterms aryl and substituted ary to include halogenated radicals. Thetotal halogen in the molecule may be on an 30 aliphatic carbon orcarbons or on an aryl carbon or carbons or located on both kinds ofcarbon atoms.

We have further ascertained that in a halogenated, arylated aliphatichydrocarbon designed to be used as an addition agent for lubricatingoils, it is necessary to have more than one aryl nucleus to onealiphatic carbon atom. In compounds having fewer aryl groups, otherproperties become significantly objectionable. Benzyl chloride, forexample, is a lachrymator and is corrosive; hence it is not suited toour-purpose.

While our emphasis is on the use of chlorine compounds because of theirready availability and cheapness, we do not wish to be limited to thisone halogen since the other halogens are suited to our purpose. Bromineand iodine are more costly than chlorine while fluorine is very activechemically.

The halogenated, arylated aliphatic hydrocarbons which we contemplateusing may be prepared by any of the methods known to the art, such asthe Friedel-Crafts reaction or other condensation reactions. They may bepurified by distillation, crystallization or other suitable process. Itis important, however, that these essences be free from any. traces of,hydrochloric or other acids, so that such corrosive substances will notbe inadvertently introduced into the blend. These may be removed bywashing the essence with dilute caustic, soda ash solutions or the like.I

In order to test various addition agents, we

- have made blends consisting of one-half percent or one percent of theadded material and 99.5

; percent or 99'percent of a well refined mineral or hydrocarbonlubricant of the viscosity of S. A. E. 30. In practicing our invention,however, the, F hydrocarbon portion of the blend may be any materialincluded in that class named, be it-natue ml or synthetic in character.It may be, for example, a hydrogenated lubricant, or one obtained by anysort of chemical or catalytic action on hydrocarbons. These hydrocarbonoils may be ofany blassificationsince the invention is not limited tooils or the-S. A. E. classification.

For the sake-oi comparison we have used 0.5% and 1% conce'ntrationsrofaddition agents in our exemplifying blends. Hbwever, it is to beunderstood that in practicing our invention any suitable concentrationof addition agent irom 0.2%

to 5% or more may be used in ordrto obtain eficts of thede'siredmagnitude. 1

These blends were then tested by recommended methods on the machinemanufactured for the purpose by the Timken Roller Bearing Company andhereafter referred to as the 'Iimken" machine. Its construction andoperation are fully described in the literature (of the art.

In order to examine the effect of introducing various substituents intoorganic molecules so as to increase the film strength of their blends,we

have found it helpful to express the efiiciency of the halogens, forexample, in the case of a halogenated addition agent, as a ratio of theTimken film strength in pounds per square inch to the percent ofchlorine present in the addition agent.

Efficiency index= Increase in film strength (pounds per sq. in.) Percentof chlorine in the addition product.

'Ihis ratio, whichwe have chosen tocall the eflialkyl halide have beensubstituted by the phenyl group. It is particularly advantageous'inthese phenylated alkyl halides to have the phenyl groupv or groupsattached either to the carbon atom which bears the halogen or to thenext carbon atom. This proximity is essential in order that theactivating influence of the negative phenyl group be effective. If thelatter be further removed, its influence decreases rapidly with theincrease in the number of carbon atoms intervening between the phenylgroup and the halogen atoms.

The specific examples given herein serve'to show how we practiceouninvention, and are not to be considered as limitations;

Example I q a Num- Timken test Elficlency bar lbs/sq. in. index 1Mineral 011 0000-1000 2 Ethylene dichloride (0.5 13, 183. 5 3Tetraphenylethylenec oride I (I It is apparent from this comparison thatwhile the introduction 01' the four phenyl groups in the ethylenedichloride increases the eflectiveness'pf the latter in improving thefilm strength, it also reduces the chlorine content of the molecule somuch that in order to make a fair comparison of the two compounds it isnecessary to take this into account. The eihciency index indicates thatsuch halogen as is'contained in the phenylated compound is more thanseven times as eflective in improving the load carrying characteristicsin the blend.

The blend oi tetraphenyl ethylene dichloride was as stable towardoxidation as the hydrocarbon oil from which it was prepared andcorrosiveness and cold testwere not adversely affected.

Example II miiii- Timken test Efllcien bet lbs.lsq.in. index 1Mineraioil 0000-7000 2* Hexyl cbloride.(1%) 0160 m8.8 3.Octadecylbromide (1%) 5110 212.9 4 Triphenyl methyl chloride (1 5!, 0104, 095. 0 5 Betahenyl ethyl chloride The eifect of phenylation is shownhere both in the Timken test and in the efflciency index, but morestrikingly in the latter. v

chloride makes but relatively poor use of halogen, beta-phenyl ethylchloride produces five times the film strength in spite of itslowerchlorine content. This is shown in the emciency in- Whilehexyl dex whichis about six and one-half times greater in the case of the moreeiiicient compound.

The high value shown for the blend of triphenyl methyl chloride provethe advantage of having one or more of the aryl groups attached to thesame carbon bearing the halogen. This compound is three times aseflicient as beta-phenyl ethyl chloride, butbeta-phenyl ethyl chlorideis much more efiicient than either of the alkyl halides. v

All of these blends were satisfactory in other respects, such as coldtest, stability, color corrosiveness. and other properties.

Example III To 99 parts of S. A. E. 30 mineral oil of high quality, onepart by weight of benzophenone dichloride was added and the twocomponents thoroughly blended together. A load of 59,000 pounds persquare inch was carried satisfactorily by this blend on the Timkenmachine, while the unblended oil carried 6,000 to 7,000 pounds persquare inch pressure. The emciency index oi! this addition agent is1966.7. All other properties of this blend were satisfactory.

Having thus described our invention, what we claim is:

1. A lubricating oil comprising in combination a hydrocarbon oil and asmall percentage of an oil soluble, phenylated, chlorinated, aliphatichydrocarbon containing the following structure:

A HB- in which A represents an aryl group.

2. A lubricating oil comprising in combination a hydrocarbon oil and a.small percentage of an oil soluble, phenylated, chlorinated, aliphatichydrocarbon containing the following structure:

A A J,

in which A represents an aryl group.

3. A lubricating oil comprising in combination a hydrocarbon'oil and asmall percentage of an oil soluble, phenylated, chlorinated, aliphatichydrocarbon containing the following structure:

